I. Field of the Invention
The present invention relates generally to excavating transplanters of the type otherwise known as tree or seedling planters. More particularly, the present invention relates to seedling planters that first cut a deep furrow with front-mounted coulter blades, and then close the furrow with trailing packer wheels after a seedling has been properly placed. Prior art of relevance to the invention is classified in United States Patent Class 111, Subclasses 101, 107, 109 and 112.
II. Description of the Prior Art
The ever-increasing worldwide demand for timber has aggravated the need for reliable and efficient replanting methods. The prior art includes numerous, mechanized seedling planters. Typically, a rigid frame includes a one or more front-mounted, ground-engaging coulter blades. Where a pair of coulter blades is employed, the coulter blades are usually angularly mounted, i.e., toed in. The coulter blades open a furrow as the device is propelled or towed. They are mounted such that the axis of rotation of each blade, while not collinear or coaxial, is coplanar. In other words, known coulter-equipped seedling planters mount the front coulter blades in a configuration similar to a three-point tractor.
After the furrow is forcibly excavated, seedlings are dropped into the resultant seedbed, either manually or through an associated feeder mechanism. Typically, the furrow is closed by a pair of trailing packing wheels, that are angularly mounted adjacent one another, and penetrate the ground adjacent furrow sidewalls. The packer wheels repack soil about the seedling roots to close the furrow, with the seedlings positioned substantially vertically in a self-supporting orientation.
The planter seen in U.S. Pat. No. 4,344,374 issued Aug. 17, 1982 generally exemplifies the latter design approach. The heavy-duty seedling planter illustrated therein comprises a rigid frame supporting a rotatable coulter blade that opens a furrow. Seedlings are inserted into the furrow by a rotary feeder wheel system. The furrow is repacked by a pair of rigid, inclined, compacting wheels trailing the machine.
In certain areas of the country, the soil largely consists of various clays. During moist conditions, the soil sticks to the blades, and clumps around various components, interfering with proper operation. Fixed, rigidly mounted coulters, are particularly affected by the build-up of mud. The constant build-up of soil necessitates frequent shutdowns for cleaning. The build-up of clay around plow structures or coulter blades and their axles can, in some cases, block the passageway through which seedlings are dropped during the reforestation planting process.